We'll probably never colonize Mars or deep space - and here's why

The main reason is that Mars is a very unhealthy place, not just for humans but for all life. Forget the temperature extremes. The biggest problem with Mars for maintaining life is that it has almost no protection against radiation. It has no iron core like Earth and thus it does not have the magnetic field that protects humans from cosmic rays and solar mass ejections.

Six feet of soil can shield against cosmic rays as can a few centimeters of water. Since hauling water to Mars hardly seems practical, unless an ample water supply is found on Mars, the "explorers" will have to be satisfied with living and exploring under the surface.

Also, the human body is so adapted to our level of gravity that almost absent gravity (as in the space station) damages bone density. In a large space craft that rotates, you can use centrifugal force to simulate gravity, but how do you do that on the surface of Mars? Not exactly a vacation and no place anyone would want to live for long.

Terraforming isn't practical unless there's a way to give the planet a magnetic field. Otherwise, the atmosphere will simply be lost to space.

I think that is the basis of most religious opposition to science. They simply say that scientists can't know anything because they don't know everything. Although there is a certain basis for such thinking from a philosophical perspective, epistemology allows us to proceed with a certain degree of confidence; all we need to understand are the assumptions on which our knowledge stands.

To really anally analyze the concept you've presented, we need to consider the scope of the discussion. Whether or not there will be descendants of humans living in 10,000 years and what they will be doing is beyond comprehension. What humans will be doing in 50 years is much more foreseeable. The further we look into the future, the greater our speculations.

I choose to limit my prognostications to about 40 years because that seems to be the limit of our petroleum based world economy. There doesn't seem to be anything up and coming to replace the convenience of petroleum, so I feel quite confident in believing that our lives are going to become much less convenient. That being said, I think deep space exploration is a luxury that is fleeting at the moment.

Not really, my point was that we don't currently have the technologies available to us that would allow us to colonize other planets. And even though this might be so in the future, it would be the distant future, I'm afraid. Not decades,but probably much longer.

Of course we are all speculating, nothing wrong with that of course, and as such we have a lot of unknowns, but what we do know does mean that at the most we can expect to see some kind of spacecraft exploring another planet in the next few decades, but don't hold your breath.

I agree that the human species is very unlikely to ever colonize off planet. The problem that I see is one of energy. We have about 40 years until petroleum becomes a precious substance rather than bulk commodity sold by the millions of barrels. I don't think people realize just how drastically our lives are going to change as this comes into effect. We won't even be able to maintain our current volumes of air travel, let alone space travel. Plastic will go way up in price and become more scarce. Every sector of industry is going to feel too much of a crunch for us to maintain an aerospace industry.

Heather, sure these are all valid objections, however please be aware that attempting to predict the future is about as hopeless as arguing with a Animal Liberation Front supporter. I mean, not so long ago we "knew" that the earth could not be older than a certain amount of time (Lord Kelvin).

Not so long ago we "knew" other things as well.

One thing we do not know for sure are our limitations in the future. Can I (on a related note) advice "Physics of the Impossible" by Michio Kaku? It's a great book somewhat related to this topic.

It's not 'predicting the future', Rob - it's just a mathematical evaluation of remaining petrol reserves and our energy consumption habits. We are slowly improving battery technology, but we will need to advance that technology in leaps and bounds in order to get the same energy/mass ratio currently offered by fossil fuels. Even then, we will not be able to produce such large volumes of energy with such incredibly small capital/labour outlays - not without something extremely novel popping up. The trends in that area though, are about as likely as a new discovery popping up tomorrow to show us speciation did not occur through evolution.

Our energy consumption habits are going to be changing. Over all, we'll be consuming less energy ten years from now, as a species, than we are today, no matter how much our population grows. That change is extremely like to be very hard on certain segments of the population because no matter how you slice the cake, someone leaves the party hungry.

Heather, I'm talking about tens, hundreds, possibly thousands of years. You are apparently thinking ahead in decades. With our current technology, colonization of Mars might be a bridge too far. And if no new technologies will be discovered in the near future in regards to energy production, it would indeed be very difficult.

However, perhaps in two thousand years we will be able to extract energy from the vacuum, or perhaps we will have more advanced forms of nuclear power.

You are talking about current events and extrapolating them into the near future, in that sense you are quite right with your predictions, and yet, to extrapolate them indefinitely is not properly justified.

I'm not saying that you are wrong, I was only attempting to add some kind of humility to the topic in regards to the future.

Rob - you are right there. I should really be talking about our current civilization rather than our species. There is no telling what we might be doing thousands of years from now - but I feel pretty confident it won't resemble the world we currently understand or the way we currently live. That is, IF we are still around.